Strain effect on electronic and lattice dynamical behaviour of two dimensional Bi, BiAs and BiSb

Abstract

The present study investigates the electronic band structure and lattice dynamical stability of 2D monolayer sheet of Bi, BiAs and BiSb using density functional theory based on first principles calculation. All these systems are semiconductor with direct bandgap. Under tensile strain the bandgap reduces and no bandgap closing is observed upto +5% strain whereas a direct-indirect-metal transition is observed for compressive strain in all these systems. The lattice dynamical stability of these materials has been studied under strain.